What is the biggest disadvantage of an underground electrical system?

The main disadvantage of an underground electrical system stems from the difficulties associated with finding faults. Underground systems are more shielded from environmental conditions and damage from weather compared to overhead lines, but this shielding makes it harder to locate and diagnose issues when they arise.

When a fault occurs in an underground system, it can be challenging to pinpoint its exact location without expensive and time-consuming excavation. Specialized equipment and techniques, such as fault locators, are often required to detect and locate faults, which can significantly extend the repair time compared to overhead systems, where issues are usually visible and more easily assessed.

This complexity in fault finding can lead to longer outages for customers, higher maintenance costs over time, and increased labor efforts to accurately locate and remedy problems, making it a significant disadvantage of underground electrical systems.